In the sport of water ski jumping using known jump skis, increases in jump distance have depended primarily on skier technique. For example, prior to a jump the skier sets up at the side of the wake opposite the ramp and accelerates by cutting across the wake to the ramp. It is the skier's ability to cut sharply, and to delay the cut toward the ramp to the last possible moment, which determines the skier's speed at the base of the ramp. The skier's technique also determines the extent to which the approach speed can be carried up the ramp. The skier must resist the tendency to "crush" on the ramp in order to achieve maximum take-off velocity. Jump distance also is affected by the skier's ability to assume and maintain the proper stance in the air, preferably with the skis splayed at a substantial, consistent angle until just before landing.
There have been improvements in ski design affecting jump distance, such as the use of advanced fiber-reinforced composites which affects the weight, strength and flex characteristics of the skis. However, the general shape of known jump skis has remained remarkably unchanged over the years. Jump skis typically are of substantially constant thickness with substantially flat tops and flat bottoms. Known jump skis have a gradual upward curvature at the tail and a sharper upward curvature at the tip; and known skis have a slight taper in width from the area of the toe of the binding toward the tail. In general, the shape of known skis has been determined primarily based on the severe on-water conditions encountered by the skier. The skis must permit skiing on the water at speeds approaching 70 miles per hour at the base of the ramp (as compared to a towing speed of 35 miles per hour). The skis also must permit the extremely sharp cut to the ramp and withstand abrupt forces applied by engagement with the ramp and with the water when landing.